Reefs.org Forums

[AF Founder]

I'm posting this message or Judy,

"EXCELLENT !!!

Especially loved the article on where the corals are collected.
Very helpful.
A question I have been asking for about 6 years now--
would you, please, refer this to someone.

Where /What exactly makes the "metallic green" ,
look to various euphylia specimens when we dealers get them??

They all revert back to normal coloration in all my coral tanks.
(ie-green and brown zooanthellae)
Am I do something wrong here??
Thank you for your help.
bye,,

Judy/The Salt Box
www.coralreeftanks.com

[AF Founder]

Judy,

My guess is that you are referring to GFP (green floursecent protein), something that Dr. Bingman has discussed several times in the past; maybe he will have something to say here. Another guess is that the color you are referring to with corals recently taken from the sea was developed by the coral in response to real sunlight.

Terry

[flameangel]

The "metallic green" color that I am referring to above, is essentially a very pale but brilliant fleurescent green. Not the white of bleached corals-but not with the depth of normal fleurescent green pigment either.
The wholesalers charge extra for these colorations, but under every light and depth tried so far- they still revert to normal coloration.
Thank you for any information.

[cbingman]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by flameangel:
<strong>The "metallic green" color that I am referring to above, is essentially a very pale but brilliant fleurescent green. Not the white of bleached corals-but not with the depth of normal fleurescent green pigment either.
The wholesalers charge extra for these colorations, but under every light and depth tried so far- they still revert to normal coloration.
Thank you for any information.</strong><hr></blockquote>

The density of symbiotic dinoflagellates tends to increase in captive corals. The amount of light that they get in a tank tends to be less than in the wild, and the concentration of nutrients in almost all reef tanks far exceeds that found in the wild. High nutrients promote high densities of symbiotic dinoflagellates.

As the amount of photosynthetic pigments increase, the fluorescence from GFP homologs is attenuated (absorbed.) Less light reaches the fluorescent molecules, so there is less total flourescence in the first place, and fluorescent light is also absorbed by the photosynthetic pigments.

Additionally, the corals that you are getting might have been collected in a bleached state or bleached during transit (bleaching being defined as a decrease in the density of symbiotic dinoflagellates.) In some cases, bleached corals can expell fluorescent pigments, but the more common outcome is that the dinoflagellates are lost, and the fluorescent pigments remain.

If you want to keep the corals looking the same as they did when they arrived, you may be chasing after something inconsistent with the future survival of the organism. Bleached corals tend not to live very long. They either recover or die.

Craig Bingman

[flameangel]

Thank you, Craig !!!
This makes perfect sense and is what I had hoped was happening.
The corals that change to the more "dense look" and more normal coloration, live and grow very well.
I would far rather they were healthy, than a certain "bright translucent color !!!

With your answer here- I can now stop worrying.
Thank you so much.
sincerely,
Judy